Flow-guiding members for gas turbine engines, etc. are widely used for aircrafts, electric generators, etc. For instance, gas turbine engines for aircrafts are provided with stator vanes acting to guide the introduced air to rotor vanes and working as outlet guide vanes for guiding a bypass flow. The stator vanes are generally made of metal materials such as titanium alloys, aluminum alloys, stainless steel, etc. The metal stator vanes are produced by forming pluralities of vanes by casting, forging, pressing, etc., and bonding each vane to a casing called a platform by welding or brazing, etc.
However, the above conventional production methods need machining, finishing, coating, etc. after the formation of vanes, resulting in a large number of working steps and difficulty in working of small complicated parts. In addition, the flow-guiding members made of metal materials are disadvantageously heavy and expensive.
Much attention has recently been paid to flow-guiding members made of composite resin materials, because they are light in weight and have satisfactory mechanical strength. A flow-guiding member made of a composite resin material generally has a structure in which among elements constituting the flow-guiding member, only vanes are changed from a metal to the composite resin material. It is produced by bonding units obtained by forming prepregs, etc. to supports one by one by an adhesive, etc., and winding a tape around the assembled units to fix them. However, inevitable dimensional errors of parts make it difficult to assemble the units to a uniform shape by such production method, resulting in difficulty in fixing the units at desired positions, and needing additional steps of winding a tape to fix the units. In addition, even when only one unit is damaged, the entire assembly should inevitably be exchanged because the units are undetachably assembled.
In such circumstances, the inventors previously proposed a flow-guiding member unit having an integral structure comprising one vane, an outer platform piece, and an inner platform piece, which is constituted by (a) a core comprising a web portion constituting the vane, and flanges integrally connected to both ends of the web portion to constitute the outer platform piece and the inner platform piece, and (b) a skin layer covering the core, the skin layer being made of a thermosetting resin having rubber or rubber elasticity (JP2003-214400A). To produce this flow-guiding member unit, for instance, a prepreg laminate is heat-pressed, charged into a die together with a liquid thermosetting resin, and the resin is cured.
Because the flow-guiding member unit having a skin layer made of a thermosetting resin has enough elasticity, it can be formed into a flow-guiding member without needing to wind a tape around it. Accordingly, when the flow-guiding member formed by the flow-guiding member units produced by this method are damaged, only damaged units can be exchanged to new ones. However, to produce flow-guiding member units having excellent mechanical strength, the prepreg laminate should be formed by cutting the prepregs to predetermined shapes and laminating them, with the directions of fibers taken into consideration. This operation requires such high skills that only skilled artisans can produce the laminate, taking an extremely long period of time and a high cost.